Hold on.
There was a complaint by a citizen to law enforcement about OP displaying "disturbing images" in a public location. That drew a series of investigative questions by local law enforcement as it would pretty much anywhere in the US.
What OP thinks about those picture and their appropriateness is not relevant. He displayed them in a public place where others who apparently don't share his views of what is appropriate, were sufficiently concerned that they called the cops.
What followed is pretty standard. This isn't a debate about where to draw the line, it is simply a statement about what one displays in public.